1. Field of Use
This disclosure is generally directed to fuser members useful in electrophotographic imaging apparatuses, including digital, image on image, and the like. This disclosure also relates to processes for making and using fuser members.
2. Background
In a typical electrophotographic imaging apparatus, an image of an original to be copied, or the electronic document image, is recorded in the form of an electrostatic latent image upon a photosensitive member and the latent image is subsequently rendered visible by the application of thermoplastic resin particles or composites thereof which are commonly referred to as toner. The visible toner image is in a loose powdered form and can be easily disturbed or destroyed. The toner image is usually fixed or fused upon a substrate or support member which may be a cut sheet or continuous media, such as plain paper.
A fuser or image fixing member, which can be a rolls or a belt, may be prepared by applying one or more layers to a suitable substrate. Cylindrical fuser and fixer rolls, for example, may be prepared by applying an elastomer or fluoroelastomer to an aluminum cylinder. The coated roll is heated to cure the elastomer.
Fuser members may be composed of a resilient layer with a fluoropolymer topcoat as the release layer. Fluoropolymers can withstand high temperature (>200° C.) and pressure conditions and exhibit chemical stability and low surface energy, i.e. release properties. For instance, fluoroplastics, such as TEFLON® from E.I. DuPont de Nemours, Inc. have a lower surface energy due to high fluorine content and are widely used for oil-less fusing.
Fluoroplastics, such as PTFE and PFA, can be applied by coating techniques onto a fuser member substrate to form a release layer. Since fluoroplastics typically require high baking temperatures (i.e. over 300° C.) to form a continuous film, which is well above the decomposition temperature of resilient layer, typically silicone (about 250° C.), the processing window for forming a fluoroplastic topcoat over a silicone-containing substrate to achieve uniform coatings without defects is extremely narrow. Cracks and bubbles are the two major defects observed during the fabrication of such fuser members. It would be desirable to have a coating method and composition that reduced or eliminated cracks and bubbles when forming the fluoroplastic topcoat. In addition, it would be desirable to provide a fuser topcoat that has a wider processing latitude.